KT-2752: refactoring:

1. Get rid of most of ManglingUtils
2. Use simple mangling for delegated properties instead of stable mangling
3. Use stable mangling for public declarations of open non-public classes
4. When generating a fresh name in a JsScope, check it for clashing against parent scopes
5. JsFunctionScope does not generate fresh name instead of stable names
6. Function scopes inherit directly from global scope
7. Generate simple mangled names for backing fields of properties

js/js.frontend/src/org/jetbrains/kotlin/js/naming/FQNGenerator.kt

@@ -187,7 +187,9 @@ class FQNGenerator {
         return when (containingDeclaration) {
             is PackageFragmentDescriptor -> descriptor.visibility.isPublicAPI
             is ClassDescriptor -> {
-                if (descriptor.modality == Modality.OPEN || descriptor.modality == Modality.ABSTRACT) {
+                if (descriptor.modality == Modality.OPEN || descriptor.modality == Modality.ABSTRACT ||
+                    containingDeclaration.modality == Modality.OPEN || containingDeclaration.modality == Modality.ABSTRACT
+                ) {
                     return descriptor.visibility.isPublicAPI
                 }
 

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameChecker.kt

@@ -16,7 +16,6 @@
 
 package org.jetbrains.kotlin.js.resolve.diagnostics
 
-import org.jetbrains.kotlin.config.LanguageFeatureSettings
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
@@ -26,7 +25,7 @@ import org.jetbrains.kotlin.resolve.SimpleDeclarationChecker
 
 object JsNameChecker : SimpleDeclarationChecker {
     override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, diagnosticHolder: DiagnosticSink,
-                       bindingContext: BindingContext, languageFeatureSettings: LanguageFeatureSettings) {
+                       bindingContext: BindingContext) {
         if (descriptor is PropertyDescriptor) {
             val namedAccessorCount = descriptor.accessors.count { AnnotationsUtils.getJsName(it) != null }
             if (namedAccessorCount > 0 && namedAccessorCount < descriptor.accessors.size) {

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt

@@ -16,7 +16,6 @@
 
 package org.jetbrains.kotlin.js.resolve.diagnostics
 
-import org.jetbrains.kotlin.config.LanguageFeatureSettings
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.js.naming.FQNGenerator
@@ -24,7 +23,6 @@ import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.psi.KtProperty
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.DeclarationChecker
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.SimpleDeclarationChecker
 import org.jetbrains.kotlin.resolve.descriptorUtil.isExtension
@@ -40,8 +38,7 @@ class JsNameClashChecker : SimpleDeclarationChecker {
             declaration: KtDeclaration,
             descriptor: DeclarationDescriptor,
             diagnosticHolder: DiagnosticSink,
-            bindingContext: BindingContext,
-            languageFeatureSettings: LanguageFeatureSettings
+            bindingContext: BindingContext
     ) {
         if (declaration !is KtProperty || !descriptor.isExtension) {
             checkDescriptor(descriptor, declaration, diagnosticHolder)

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/OverriddenJsNameChecker.kt

@@ -1,77 +0,0 @@
-/*
- * Copyright 2010-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.kotlin.js.resolve.diagnostics
-
-import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
-import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
-import org.jetbrains.kotlin.diagnostics.DiagnosticSink
-import org.jetbrains.kotlin.js.naming.FQNGenerator
-import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
-import org.jetbrains.kotlin.psi.KtDeclaration
-import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.DeclarationChecker
-
-class OverriddenJsNameChecker : DeclarationChecker {
-    private val fqnGenerator = FQNGenerator()
-
-    override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, diagnosticHolder: DiagnosticSink,
-                       bindingContext: BindingContext) {
-        doCheck(descriptor) { first, second ->
-            val psi = descriptor.findPsi() ?: declaration
-            diagnosticHolder.report(ErrorsJs.JS_NAME_OVERRIDE_CLASH.on(psi, first, second))
-        }
-
-        if (descriptor is ClassDescriptor) {
-            val fakeOverrides = descriptor.defaultType.memberScope.getContributedDescriptors().asSequence()
-                    .mapNotNull { it as? CallableMemberDescriptor }
-                    .filter { it.kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE }
-            for (override in fakeOverrides) {
-                val errorFound = doCheck(override) { first, second ->
-                    val psi = descriptor.findPsi() ?: declaration
-                    diagnosticHolder.report(ErrorsJs.JS_NAME_OVERRIDE_CLASH.on(psi, first, second))
-                }
-                if (errorFound) break
-            }
-        }
-    }
-
-    private fun doCheck(descriptor: DeclarationDescriptor, onClash: (CallableMemberDescriptor, CallableMemberDescriptor) -> Unit):
-            Boolean {
-        if (descriptor !is CallableMemberDescriptor) return false
-
-        var knownName: String? = null
-        var knownDescriptor: CallableMemberDescriptor? = null
-        for (overridden in descriptor.overriddenDescriptors) {
-            val fqn = fqnGenerator.generate(overridden)
-            if (!fqn.shared) continue
-
-            val name = fqnGenerator.generate(overridden).names.last()
-            if (knownName == null) {
-                knownName = name
-                knownDescriptor = overridden
-            }
-            else if (knownName != name &&
-                     (AnnotationsUtils.getJsName(knownDescriptor!!) != null || AnnotationsUtils.getJsName(overridden) != null)) {
-                onClash(knownDescriptor, overridden)
-                return true
-            }
-        }
-
-        return false
-    }
-}